Mouse models play a critical role in linking together cancer biology, drug discovery and developmental therapeutics, and are a necessary step to test the clinical relevance of basic observation to human cancer (translational research). Over the last several years, imaging modalities have revolutionized the use of murine models as preclinical models by providing new tools to longitudinally and quantitatively monitor cancer progression and response to therapy in these models. The overall goal of the Small Animal Model and in vivo Imaging Core (Core D) is therefore to provide well established and standardized preclinical murine models to test biological hypotheses and novel therapeutic modalities as well as standardized and state of the art imaging technologies to more accurately and efficiently monitor tumor progression and therapeutic response. The specific aims of this core are therefore: Aim #1: To be a central resource providing a series of standardized neuroblastoma xenograft models including subcutaneous injection, orthotopic implantation, experimental bone metastasis and bone invasion models, performing daily tumor monitoring, and administering therapeutic agents. The core will also perform euthanasia and provide tissue suitable for analysis to individual investigators or to core B. Aim #2: To be a central resource for the performance of in vivo imaging using high resolution X-rays, optical imaging techniques, microMagnetic Resonance Imaging (MRI) and radionuclide based Single Photon Emission Computer Tomography (SPECT), and to provide expertise for acquisition, interpretation and analysis of imaging data. This core will be a critical link between Project 1, 2 and 3 and project 4 by generating preclinical data identifying novel therapeutic modalities to be then tested and validated in clinical trials.